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1/*
2 * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright IBM Corporation, 2008
19 *
20 * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
21 *
22 * For detailed explanation of Read-Copy Update mechanism see -
23 * Documentation/RCU
24 */
25#ifndef __LINUX_TINY_H
26#define __LINUX_TINY_H
27
28#include <linux/cache.h>
29
30static inline void rcu_init(void)
31{
32}
33
34#ifdef CONFIG_TINY_RCU
35
36static inline void synchronize_rcu_expedited(void)
37{
38 synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
39}
40
41static inline void rcu_barrier(void)
42{
43 rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
44}
45
46#else /* #ifdef CONFIG_TINY_RCU */
47
48void rcu_barrier(void);
49void synchronize_rcu_expedited(void);
50
51#endif /* #else #ifdef CONFIG_TINY_RCU */
52
53static inline void synchronize_rcu_bh(void)
54{
55 synchronize_sched();
56}
57
58static inline void synchronize_rcu_bh_expedited(void)
59{
60 synchronize_sched();
61}
62
63static inline void synchronize_sched_expedited(void)
64{
65 synchronize_sched();
66}
67
68#ifdef CONFIG_TINY_RCU
69
70static inline void rcu_preempt_note_context_switch(void)
71{
72}
73
74static inline void exit_rcu(void)
75{
76}
77
78static inline int rcu_needs_cpu(int cpu)
79{
80 return 0;
81}
82
83#else /* #ifdef CONFIG_TINY_RCU */
84
85void rcu_preempt_note_context_switch(void);
86extern void exit_rcu(void);
87int rcu_preempt_needs_cpu(void);
88
89static inline int rcu_needs_cpu(int cpu)
90{
91 return rcu_preempt_needs_cpu();
92}
93
94#endif /* #else #ifdef CONFIG_TINY_RCU */
95
96static inline void rcu_note_context_switch(int cpu)
97{
98 rcu_sched_qs(cpu);
99 rcu_preempt_note_context_switch();
100}
101
102/*
103 * Take advantage of the fact that there is only one CPU, which
104 * allows us to ignore virtualization-based context switches.
105 */
106static inline void rcu_virt_note_context_switch(int cpu)
107{
108}
109
110/*
111 * Return the number of grace periods.
112 */
113static inline long rcu_batches_completed(void)
114{
115 return 0;
116}
117
118/*
119 * Return the number of bottom-half grace periods.
120 */
121static inline long rcu_batches_completed_bh(void)
122{
123 return 0;
124}
125
126static inline void rcu_force_quiescent_state(void)
127{
128}
129
130static inline void rcu_bh_force_quiescent_state(void)
131{
132}
133
134static inline void rcu_sched_force_quiescent_state(void)
135{
136}
137
138static inline void rcu_cpu_stall_reset(void)
139{
140}
141
142#ifdef CONFIG_DEBUG_LOCK_ALLOC
143extern int rcu_scheduler_active __read_mostly;
144extern void rcu_scheduler_starting(void);
145#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
146static inline void rcu_scheduler_starting(void)
147{
148}
149#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
150
151#endif /* __LINUX_RCUTINY_H */